Problem when adding fields and using WP core remove_submenu_page() function

Hi there,

just noticed there's an issue when adding new fields to an existing form and using the remove_submenu_page() function on special plugins, ie. like this:
remove_submenu_page('index.php', 'relevanssi/relevanssi.php');

the error log then throws a
PHP Warning: Invalid argument supplied for foreach() in /.../wp-admin/includes/plugin.php on line 1286
which is odd because the code there is the remove_menu_page function, actually not responsible for submenus items.
The Fields are added though, so no critical issue so far.

Don't know if it's really an GF-issue but afaik this warning is only thrown with GF on adding fields yet.

Hey, just realized it was the wrong hook used to trigger the custom function.
It had nothing to do with GravityForms since i also found this error on other core functions now.

needed to use the correct hook 'admin_menu' instead according to this thread:
http://wordpress.org/support/topic/using-remove_menu_page-causes-error-throughout-other-admin-sections

so, all solved!

regards,
daniel